The invention relates in general to exhaust gas treatment devices and in particular to a new and useful device for catalytic cleaning of exhaust gases of an internal combustion engine, which has a metallic catalyst carrier of flat and corrugated metal strips arranged in layers and mounted in a metallic housing, and a method for its manufacture.
Similar catalyst carrier bodies, mounted in a metallic housing, are known, e.g. from German laid-open specification 23 02 746, according to which a plain and a corrugated strip are brought together and wound together so that a catalyst body is created in which the strips are wound spirally around a core. This arrangement has the considerable disadvantage, in particular that because of the pulsation of the exhaust gas the core is forced out, so that a conical deformation takes place in the direction of the axis.
In addition, a catalyst carrier body is known from EURO application 245 737, in which the forcing out of the core is delayed. In this known arrangement, the catalyst carrier body is formed in such a manner that in a stack of textured sheets, the ends are interlaced in an opposite direction around two fixed points, and a jacket is slipped over this coil form. According to the process therein disclosed, bodies of different shapes can be formed, with the starting point in each case being a stack of textured sheets, and manufacture takes place over fixed points determined in advance, with forks or similar devices engaging in the fixed points. In the case of special shapes, e.g. for oval catalyst carrier bodies, it is necessary to work with separately produced filling bodies which are inserted into the wound body. Though the danger of the body being forced out, or its being deformed in the axial direction is reduced in this arrangement, the danger is not completely avoided, with deformation occurring especially then when the individual wound layers are undetachably connected to the jacket, e.g. by soldering. This is carried out with a geometrical, strictly symmetrical structure.